Electronic medical thermometers that estimate a patient's body temperature have been in common use in the medical community for a number of years. From neonates to the elderly, measuring body temperature can be a critical factor in the treatment of problems or diseases of patients. Thus, determining an individual's body temperature in an accurate, and noninvasive manner is essential to providing proper care to a patient. However, a patient views the temperature taking process as intrusive and uncomfortable, especially the neonate.
In the past, electronic thermometers typically included an elongated probe that contained a thermal resistor (thermistor) within the tip of the probe. The traditional digital “stick” thermometers were usually designed for three-way use in the oral, rectal, and axillary regions. A hygienic cover would be placed over the tip of the probe where the thermistor was situated, or utilized without a cover and subsequently cleaned in an alcoholic bath, then the probe would be applied to the particular location on the patient's body. From there, the temperature of the thermistor and probe would begin to rise toward the patient temperature and the thermometer would use algorithms to process the thermistor signal and predict the temperature of the patient. The predicted temperature of the patient would be displayed on the thermometer before the thermistor's temperature would actually reach that predicted temperature. Other sensors conventionally in use similarly utilize a thermistor, however rather than using prediction algorithms they convert the actual measured resistance in the thermistor into a temperature which is displayed to a user.
Traditional glass and mercury-filled thermometers typically take about three minutes in order to obtain an accurate temperature of an individual. The prediction algorithms used in electronic thermometers provide reasonably accurate temperature predictions within about 30 seconds after the thermometer is applied to the patient's body. The long measurement time for a glass thermometer is mainly due to the heat capacity of the glass probe and also due to the reduction in temperature of the tissue in the immediate area where the probe is applied.
Although existing electronic thermometers have proven successful in reducing measurement times and obtaining an accurate temperature of an individual, there is a need for an improved electronic thermometer that is site-specific to the axillary region, provides for greater comfort to patients, and increases the accuracy and speed with which the temperature is measured.